Knitting machine



H. H. HOLMES Sept. 8, 1936,

KNITTING MACHINE Filed Apil 2o, 1954 2 sheets-sheet 1 Sept 8, 11.936. l H. H. HOLMES v 2,053,477

KNITTING MACHINE l Filed April 20, 1934 2 Sheets-Sheet 2 Patented Sept. 8, 1936 UNITED STATES PATENT OFFICEA Application April 20, 1934, Serial No. 721,587 In Great Britain April 21, 1.933

s claims. (o1. 66-135) This invention consists in improvements in or relating to knitting machines and has. .for its object tofprovide an improvedrnechanism Whereby Warp-threads caribe knitted in combination with a ground-thread or threads to render the resultant fabric ladderproof or substantially ladderproof Within .the meaning of that term as defined in the specications of. prior United States applic-ations Nos. 415,659, 416,458-, l600,780 and British Letters PatentNo. 376,736.

In prior United States applications Nos. 415,659 and 416,458, fabric has been described in` which thel portion Lformed Yfrom vthe ground-thread .served asa basis upon which the VWarp-threads Were plated to appear on the front of the fabric. While afabric of this natureisladderproof Within the meaning of the term as defined, it suffers from ,the disadvantage that the appearance of the facefof the fabric is to some extent marred bythe presence of the Warp-threads. This drawback is obviatedwhen the fabric is knitted in accordance Avvithgthedescription given in, Prior `United States application No. 600,780 and British latent` No. 376,736 ifby ywhich the Warp-threads are platedin rear of theground-thread, A fabric of this kind is of special advantage for h ose and half-hosebecause'theouter surface exposed to `vievv'differs onlyveryslightly and is almost .indistinguishable fromf-a -plain knit fabric pro.- aduced from ground-thread only.

Means for improving the rear-plating of the Warp-threads or-for ensuring aA good quality of rear-platinghave been described. in thespecications of lprior `United States applications Nos. 642,254 and 642,246 by Which each Warp-thread isi/released priortovthe loop-drawing operation of the needlev taking the thread, and the present invention, although it is not-limited tov employment in conjunction with such thread-releasing means may be employed in addition thereto with benet to the resultant fabric. The invention is ,1 applicable-to any-mechanism whereby a ladder-v proof fabric is produced from combined groundand .Warp-threads -and in which means is provided-whereby, prior to loop formation on each needle ai lengthof Wale-thread required for each loopisfdrawn offindependently of the needle ymovement as, for instance, bythe members 34, 35=and,36 ofv prior British Patent No. 364,039 or .cam` 3l of. prior United States application No. v642,254. lSuch means .will bereferred to hereinl.after as a draw-off device.

According ,to the present invention the threaddrawing .device isv so formed, or iscombined with ,other means which Willoperate in an equivalent have to provide a surplus of the individual Warp` threads over and above that required 1.9 individual loops.

For instance, it is possible to form the loopdrawing device with a cam-.rise which ,will-impart :for the the required slight additional `pull substantially at the'moment. 0f Completion cf the loop-,drawing .1.5 movement of the needle.

rIhis improvement is of `particular advantage in rear-plated-Warp-thread fabricbecause if, during formation of .any loop, a surplus of. warpthread is available beyond-that required for the `20 .loop formation the tendency vis for the Warp- -thread to ooze through thefabric to show somewhat on the face or rightside thereof. Such oozing spoils the appearance of the fabric and this is obviated in the present inventionl by4 elimination of the surplus Warp-thread atthe moment of loop formation.y l

IIn order that the invention may be more clearly .understood a preferred construction of apparatus embodying the invention kWill now be described with the aid of the accompanying gdrawings, in Which- Figure l is an elevation partly in section of thoseparts of aknitting machine and warpthread feeder. mechanismsucient to ShOW ther35 .essentialfeatures of the invention,

Figure `la, is a View looking from the right of Figure 1 to show onlyl the stitch-cam and one of the needles intheir relative positions at the f moment of engagement of a warp-thread bythe 440 additional tensioning device according to the invention, and

, Figure 2 isa plan on the line 1 -2 of Figure 1. Like reference numerals indicate like parts in the several figures of the drawings. VA5

In the portion of the mechanism illustrated the needle-cylinder is shown at I 0 with one needle I I in position. It will be understoodl that thecylinder-will be completely filled with needles lin the ordinary way. The cam-box is indicatedo at I2, the sinker-camringat I3 and Sinkersat I4.

Coaxial with the needle-cylinder and immediately above itis `the feeder-head similar in its .main essential to that described in Ldetail in .the

specification of prior British `Iietters Patentdo.liti

for instance in' copending United States application No. 722,272 to hold its Warp-thread forwardly in the needle during the last portion of the descent of the needle down the stitch-cam.

As described in the last-mentioned specification the cam serving normally to move the threadguides outwardly at the commencement of .their wrapping operation is indicated at VII and the reprojecting cam is shown at I8. Cam Ill acts as described in British patent specification No.

364,039 to deflect the thread-guides subsequently to their projection by the cam I1 in order to bring about'the wrapping movement ofthe thread-guides.

A cam-ring 20 is now provided to act as a draw-olf member for the warp-threads and is formed with a` gradual ris-e 2I which draws off in succession from each warp-thread supply an amount of Warp-thread suficient for the wrapping operation and releases the drawn off thread to the needles as the thread-guide is deflected laterally by vcam -IS andV returned inwardly by a return cam (not illustrated) Yassociated with cam I'I. A second cam-rise reaches its highest point at 22 and serves as a second thread drawoff cam to draw off amounts of warp-thread required for loop formation as the needle descends the stitch-cam. Y In accordance with the present invention an additional cam 23, circumferentially adjustable on the cam-ring 20 by means of screws'24 and a slot 25 in the cam-ring, is provided to press on thewarp-thr-eads to apply the requisite tension immediately4 prior to the knocking over pointin the loop-drawing operation. The relative positions of cam 23, feeder I5, needle I I,and stitch-cam 26 are clearly indicated in Figures 1 and 1a in which Figure la shows the relative positions of the stitch-cam and needle substantially at the time of knocking over, and Figure 1 (taken in conjunction with Figure 2) shows at the same moment the relative positions of the needle, thread-guide and cam 23.

It will be observed that the cam-rises 2I and 22 take the place of the draw-off members 34 and 36 respectively illustrated in prior British Patent No. 364,039. Also the cam-rise 22 may be considered as theV equivalent of the cam 3l in United States patent application No. 642,254.

The wrap-threads, indicated in the drawings by the reference Vnumeral II5 will, in their passage fromv the wrap-thread supply bobbins to 'the wrap-thread feeders I5 be subjected to any desired and known form of tensioning as this follows the usual practice in knitting machines employing wrap-threads. It will be understood,

therefore, that the cam rises 2l and 22 will drawoff the required amounts of wrap-threads on each operation and will yield those threads under the normal tension to the Vneedles during wrapping and loop-forming operations. As the tensioning means which are operable on the `Wrap-threads in their passage to the feeders I5 are well known and their action well understood, andm,oreover, as of themselves they constitute no part of the present invention, illustration of them is unnecessary. Y

other preferred manner to operate in a similar Way.

' Briefly the operation of the mechanism described is as follows:

'. Afterveach individual needle has been raised its associated thread-feeder is first moved outwardly by cam II on one side of the needles and at the saine time the cam 2I draws off from the warp-thread supply of that feeder a length of a thread suflicient for the purpose of wrapping round the needle. vThe feeder is then deflected by cam I9 and is retracted past theother side of the needle -by the return Ycam co-operating with cam II, vthus completingthe wrapping movement. During the completion of the Wrapping the yarn is yielded to the needle down the rearslope of'camV 2|, the relative direction of mov@- ment-fof that cam with respect to the warpthreads being indicated' by the arrowV in Figure 2. 'Ihe cam-ring 20 continues to rotate in the same direction and at a later stage-in the operation each ofthe warp-threads is engaged by the cam 22 to draw off a further supply of thread sufficient for loop formation. After this has been completed the stitch-cam commences to act upon the needle and as it nears the lowest point of the stitch-cam, cam I8 reprojects the feeder into the position illustrated on the right-hand side of Figure 1 so as to hold the warp-thread forwardly into the hook of the needle in order to assist in accurately plating the warp-threads in rear ofthe ground-thread in the finished fabric. Just as each needle reaches the lowest part of the stitch-cam 26, cam 23 engages its warp- Vthread to apply the Yrequisite slight' tension in accordance with the present invention.

I claim:

1. In a knitting machine the combination of a bed of needles, feeding means to supply ground and wrap threads to the needles, needle actuating means, a wrap thread draw-oifdevice for drawing lengths of thread required for loop formationV and to yield those threads to theV needles undertension, and means to impart to the Wrap threads, substantially at the moment of completion of the loop-drawing movements of the needles taking those'threads a momentary tension in order to apply an increased pull on the wrap threads to'assist in positioning them in their respective needle heads relatively to the ground thread.

2. In a knitting machine the combination of a bed of needles, feeding means to supply ground and wrap threads to the needles, needle actuating means, wrap thread draw-off means to draw from each wrap thread supply for each loop forming operation of the needles substantially the lengths of thread required for loop formation and `to yield those lengths to the needles under substantially constant tension, and means operating on each wrap thread to apply a momentary tension thereto to effect an increased pull on the wrap threads substantially at the moment of completion-of the loop-drawing operations.

and wrap threads to the needles, needle actuating means, and a wrapping thread draw-olf device comprising a cam plate having at least two cam rises one of which engages the threads to draw off from each wrap thread supply an amount of thread required for loop formation and another of which serves to apply a momentary tension to the wrap threads to effect an increased tension thereon substantially at the moment of completion of the loop-drawing movements of the needles.

4. In a knitting machine the combination acoording to claim 3 in which the cam plate has three cam rises two of which functionas already claimed and the third of which serves to draw off from each wrap-thread supply an amount of yarn required for wrapping the needles prior to supplying the needles with thread for loop formation.

5. In a knitting machine the combination of a bed of needles, feeding means to supply ground and wrap threads to the needles, needle actuating means, and a wrap thread draw-off device comprising a cam plate coaxial with the needle bed and having on it at least two cam rises one of which engages the threads to draw oi from each wrap thread supply an amount of thread required for loop formation, and another of which serves to apply a momentary tension to the wrap threads to effect an increased pull thereon substantially at the moment of completion of the loop-drawing movements of the needles.

6. In a knitting machine the combination according to claim 5 in which the cam plate has three cam rises two of which function as already claimed and the third of which serves to draw off from each wrap-thread supply an amount of yarn required for wrapping the needles prior to supplying the needles with thread for loop format-ion.

7. In a knitting machine the combination of a bed of needles. feeding means to supply ground and wrap threads to the needles, needle actuating means, draw-off means operable on the wrap threads to draw oif and supply to the needles for each needle operation the required amount of yarn under normal tension, and additional means operable on the wrap threads substantially at the moment of completion of the loop-drawing movements of the needles taking those threads to apply a momentarily increased tension to the threads.

8. In a knitting machine the combination of a bed of needles, feeding means to supply ground 20 and wrap threads to the needles, needle actuating means, means to draw off and supply to the needles under normal tension the amount of wrap thread required for the needle wrapping movement, means operating thereafter to draw oi and supply to the needles the amount of wrap thread required for loop formation, and additional means operable on the wrap threads to apply a momentarily increased tension substantially at the moment of completion of the loop- 30 drawing movements of the needles taking those threads.

HENRY HAROLD HOLMES. 

